'\" te
'\"! tbl|eqn | mmdoc
'\"macro stdmacro
.ds Vn Version 1.2
.ds Dt 24 September 1999
.ds Re Release 1.2.1
.ds Dp Jan 14 18:30
.ds Dm 01 normalpoi
.ds Xs 28721 6 normalpointer.gl
.TH GLNORMALPOINTER 3G
.SH NAME
.B "glNormalPointer
\- define an array of normals

.SH C SPECIFICATION
void \f3glNormalPointer\fP(
GLenum \fItype\fP,
.nf
.ta \w'\f3void \fPglNormalPointer( 'u
	GLsizei \fIstride\fP,
	const GLvoid \fI*ptr\fP )
.fi

.EQ
delim $$
.EN
.SH PARAMETERS
.TP \w'\fIstride\fP\ \ 'u 
\f2type\fP
Specifies the data type of each coordinate in the array. 
Symbolic constants
\%\f3GL_BYTE\fP,
\%\f3GL_SHORT\fP,
\%\f3GL_INT\fP,
\%\f3GL_FLOAT\fP, and
\%\f3GL_DOUBLE\fP 
are accepted. The initial value is \%\f3GL_FLOAT\fP. 
.TP
\f2stride\fP
Specifies the byte offset between consecutive normals. If \f2stride\fP is 0\-
the initial value\-the normals are understood to be tightly packed in
the array.
The initial value is 0.
.TP
\f2ptr\fP
Specifies a pointer to the first coordinate of the first normal in the
array. 
The initial value is 0.
.SH DESCRIPTION
\%\f3glNormalPointer\fP specifies the location and data  of an array of normals
to use when rendering.
\f2type\fP specifies the data type of
the normal coordinates and \f2stride\fP gives the byte stride from one
normal to the next, allowing vertices and attributes
to be packed into a single array or stored in separate arrays.
(Single-array storage may be more efficient on some implementations;
see \%\f3glInterleavedArrays\fP.)
When a normal array is specified, \f2type\fP, \f2stride\fP, and \f2ptr\fP are
saved as client-side state.
.P
To enable and disable the normal array, call \%\f3glEnableClientState\fP and 
\%\f3glDisableClientState\fP with the argument \%\f3GL_NORMAL_ARRAY\fP. If
enabled, the normal array is used 
when \%\f3glDrawArrays\fP, \%\f3glDrawElements\fP, or \%\f3glArrayElement\fP is called.
.P
Use \%\f3glDrawArrays\fP to construct a sequence of primitives (all of the
same type) from prespecified vertex and vertex attribute arrays.
Use \%\f3glArrayElement\fP to specify primitives
by indexing vertices and vertex attributes and \%\f3glDrawElements\fP to
construct a sequence of primitives by indexing vertices and vertex attributes.
.SH NOTES
\%\f3glNormalPointer\fP is available only if the GL version is 1.1 or greater.
.P
The normal array is initially disabled and isn't accessed when
\%\f3glArrayElement\fP, \%\f3glDrawElements\fP, or \%\f3glDrawArrays\fP is called.
.P
Execution of \%\f3glNormalPointer\fP is not allowed between 
\%\f3glBegin\fP and the corresponding \%\f3glEnd\fP,
but an error may or may not be generated. If an error is not generated,
the operation is undefined.
.P
\%\f3glNormalPointer\fP is typically implemented on the client side.
.P
Since the normal array parameters are client-side state, they are not
saved or restored by \%\f3glPushAttrib\fP and \%\f3glPopAttrib\fP.
Use \%\f3glPushClientAttrib\fP and
\%\f3glPopClientAttrib\fP instead.
.SH ERRORS
\%\f3GL_INVALID_ENUM\fP is generated if \f2type\fP is not an accepted value.
.P
\%\f3GL_INVALID_VALUE\fP is generated if \f2stride\fP is negative.
.SH ASSOCIATED GETS  
\%\f3glIsEnabled\fP with argument \%\f3GL_NORMAL_ARRAY\fP
.br
\%\f3glGet\fP with argument \%\f3GL_NORMAL_ARRAY_TYPE\fP
.br
\%\f3glGet\fP with argument \%\f3GL_NORMAL_ARRAY_STRIDE\fP
.br
\%\f3glGetPointerv\fP with argument \%\f3GL_NORMAL_ARRAY_POINTER\fP
.SH SEE ALSO 
\%\f3glArrayElement(3G)\fP,
\%\f3glColorPointer(3G)\fP,
\%\f3glDrawArrays(3G)\fP,
\%\f3glDrawElements(3G)\fP,
\%\f3glEdgeFlagPointer(3G)\fP,
\%\f3glEnable(3G)\fP,
\%\f3glGetPointerv(3G)\fP,
\%\f3glIndexPointer(3G)\fP,
\%\f3glInterleavedArrays(3G)\fP,
\%\f3glPopClientAttrib(3G)\fP,
\%\f3glPushClientAttrib(3G)\fP,
\%\f3glTexCoordPointer(3G)\fP,
\%\f3glVertexPointer(3G)\fP
